1. Field of the Invention
The invention relates to a reverser for a watercraft which allows the watercraft to go astern.
2. Description of the Related Art
A watercraft which is propelled by a water jet pump, for example, a personal watercraft (which is also referred to as a "PWC") has such a structure as to suck water (including sea water) through a water intake hole provided on the bottom of a hull, to pressurize the water by the water jet pump and to eject the water rearward from the hull through an outlet port of the water jet pump, thereby advancing the PWC.
To go in reverse, a deflector liftably (movably) provided behind the steering nozzle is positioned in a portion behind the steering nozzle (brought down), thereby changing the direction of the water flow ejected rearward from the steering nozzle into a forward direction. Thus, the watercraft can go in reverse.
As described in Japanese Utility Model Publication No. Hei 5-13677 (U.S. Pat. No. 4,708,671), a reverser for a watercraft according to the prior art comprises a deflector having a lower end which can be positioned below the bottom in a reverse state and having a semibowl-shaped inner face. By the shape of the inner face and the position of the lower end of the deflector, the direction of the water flow discharged rearward from the pump nozzle is changed such that the water flow is ejected forward in a region under the bottom.
With such a structure, if the reverser is to function effectively, it is necessary that the water flow should be smoothly ejected forward from the lower end of the deflector along the bottom face of a rear end of the watercraft body which is hollowed out slightly upward.
However, the bottom face of the rear end of the body is significant in enhancing planing performance when the watercraft is going forward. It is desirable that this portion should form a rectilinear bottom face as continuously as possible from a forward region thereof.